While maybe not as well covered as other thriller sub-genre's, the female-psycho has been something of a staple for the last several decades. Older titles like "Fatal Attraction," "The Hand That Rocks the Cradle," and "The Crush" paved the way for recent updates like "Obsessed" or even "Orphan." The formula is usually pretty simple: a woman, typically an attractive and otherwise unthreatening woman, slowly reveals herself to be batshit insane.

For better or worse, horror is probably the most gimmick-friendly genre. From William Castle blurring the line between cinemas and funhouses to Ruggero Deodato pulling a publicity stunt that ended with him facing homicide charges all the way up to today’s digital 3D and First Person POV movies, it’s sometimes hard to tell what came first, the gimmick or the movie.